Many vehicles have a suspension system. When a vehicle travels over a bump or a hole in a road, the suspension system can control various forces between a sprung mass of the vehicle and the road which provides a smooth ride. For example, some cars and trucks have been designed with a suspension system including a coil-over shock having a coil spring and a piston cylinder device. The coil spring surrounds the piston cylinder device, and the coil spring and the piston cylinder device cooperate to generate forces that dampen movement of the sprung mass.
Additionally, some truck designs include a suspension system having a torsion bar that acts as a spring. The torsion bar is utilized instead of the coil spring discussed above. The torsion bar is attached to an outside surface of a lower control arm and a wheel knuckle is coupled to the lower control arm. The torsion bar is twisted to apply a moment force that acts on the lower control arm as a vertical force to suspend the sprung mass of the truck. A large packaging space is utilized to provide room for the torsion bar to be attached to the lower control arm at the outside surface.
In addition, some sport cars have been designed having a spoiler on a trunk of the car to increase a downforce applied to the sprung mass of the car. The suspension system of the car can include the coil-over shock discussed above. The downforce applied to the sprung mass of the car due to the spoiler can cause the sprung mass of the car to move downwardly toward the road. To counteract this downforce, a hydraulic actuator can be operatively coupled to the coil-over shock to adjust the seat height of the coil spring of the coil-over shock. Adjusting the seat height changes the amount of compression of the coil spring that counteracts the downforce. Another alternative to counteract this downforce is to utilize a heave spring, which is operatively coupled to the coil-over shocks of opposing wheels, and in this configuration, can counteract the downforce when both sides of the vehicle experience simultaneous vertical travel.